---------------------------------------------------------------------------ValueError Traceback (most recent call last)
<ipython-input-176-783031542db4> in <module>()----> 1sign(data)<ipython-input-173-888533a22840> in sign(x) 1def sign(x):----> 2if x <0: 3return-1 4else: 5return1ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()